The story of the adventure in space and time of Meg, Charles Wallace, and Calvin O'Keefe (athlete, student, and one of the most popular boys in high school). Meg Murry and her friends become involved with unearthly strangers and a search for Meg's father, who has disappeared while engaged in secret work for the government on the Tesseract problem

Meg Murry, her brother Charles, and their friend Calvin, embark on a journey through space and time, assisted by three otherworldly women, when they set out to find Meg's father, a physicist who disappeared while experimenting with time travel